Vitamin B3 (niacin, nicotinic acid, nicotinamide, niacinamide)

Vitamin B3 is also known as niacin, nicotinic acid, nicotinamide, niacinamide and antipellagra vitamin or PP factor. Niacin is a water-soluble vitamin whose derivatives such as NADH play essential roles in energy metabolism in the living cell. Niacin works closely with vitamin B1, vitamin B2, vitamin B6, pantothenic acid, and biotin to break the carbohydrates, fats, and proteins in food down into energy. Vitamin B3 is essential in the metabolism of carbohydrates (to produce energy), fats, and proteins.

It also aids in the production of hydrochloric acid, needed for proper digestion. Additionally, vitamin B3 facilitates the body's ability to eliminate toxins. The name niacin derives from nicotinic acid + in. When the properties of niacin were discovered, it was thought prudent to choose a common name other than nicotinic acid, for fear that it might be confused with nicotine, leading to the ideas that either smoking provided vitamins or that wholesome food contained a poison.

Niacin plays an important role in ridding the body of toxic and harmful chemicals. It also helps the body make various sex and stress-related hormones in the adrenal glands and other parts of the body. Vitamin B3 is essential for the activity of many enzymes in the body. Enzymes are special substances that speed up chemical reactions in the body. These enzymes are responsible for the production of energy in the body, the breakdown of dietary fats, the production of certain hormones and cholesterol, the processing of genetic material (DNA) and the growth and maturation of the cells in the body. Niacin is effective in improving circulation and reducing cholesterol levels in the blood. Niacin needs can be partially met by eating foods containing protein because the human body is able to convert tryptophan, an amino acid, into niacin.

Niacin, via its metabolites, is involved in a wide range of biological processes, including the production of energy, the synthesis of fatty acids, cholesterol and steroids, signal transduction, the regulation of gene expression and the maintenance of genomic integrity. Nicotinic acid, in pharmacological doses, is used as an antihyperlipidemic agent. Vitamin B3 (Niacin) increases good cholesterol (HDL) and lowers bad cholesterol (LDL). Niacin may enhance the effectiveness of some medications prescribed to lower cholesterol.

Vitamin B3 comes in two basic forms - niacin (also called nicotinic acid) and niacinamide (also called nicotinamide). A variation on niacin, called inositol hexaniacinate, is also available in supplements. Niacin can be found in nuts, dairy products, lean meats, poultry, fish, and eggs. Some niacin is also supplied by legumes and enriched breads and cereals. The best dietary sources of vitamin B3 are found in beets, brewer's yeast, beef liver, beef kidney, pork, turkey, chicken, veal, fish, salmon, swordfish, tuna, sunflower seeds, and peanuts. The body can synthesize niacin from the essential amino acid tryptophan, but the synthesis is extremely slow; 60 mg of tryptophan are required to make one milligram of niacin.

For this reason, eating lots of tryptophan is not an adequate substitute for consuming niacin. As serotonin synthesis is reliant on tryptophan availability, inadequate dietary intake of vitamin B3 may also therefore lead to depression. The liver is the main storage area for this vitamin and absorption of vitamin B3 takes place in the intestines. Vitamin B3 is required by the body for digestive processes, activating enzymes which nourish the brain, regulating blood pressure and regulating cholesterol levels.

Vitamin B3 (niacin) functions, uses, and health benefits

Niacin is a water-soluble vitamin that participates in more than 50 metabolic functions, all of which are important in the release of energy from carbohydrates. Because of its pivotal role in so many metabolic functions, niacin is vital in supplying energy to, and maintaining the integrity of, all body cells. Niacin also assists in antioxidant and detoxification functions, and the production of sex and adrenal hormones. Vitamin B3 (niacin, niacinamide, nicotinic acid) lowers cholesterol by preventing its buildup in the liver and arteries.

Niacin moves fat from tissues for fat metabolism, burning it for energy. It promotes healthy skin, the health of the myelin sheath (the protective covering of the spinal nerves), and good digestion, where it is also vital for the production of hydrochloric (stomach) acid. It is an aid in protecting the pancreas, and is necessary for the health of all tissue cells.

Niacin releases histamine that dilates the blood vessels, which produces heat, redness, and occasional itching of the face, chest, back and legs. This flushing aids circulation, is temporary, and usually passes after ten or fifteen minutes. Niacin also dilates the capillaries of the brain and other tissues. It can help to relieve negative personality behavior such as schizophrenia, depression, delusions, and dementia. Niacin can also help relieve acne, migraines, vertigo, forgetfulness, high blood pressure and diarrhea. Niacin, in synergy with chromium improves blood sugar regulation by helping insulin function.

Niacin is instrumental in relieving symptoms of schizophrenia such as paranoia and hallucinations; Niacin has helped elderly patients regain mental clarity; because it dilates blood vessels, niacin brings more oxygen to the brain. Niacin has helped insomniacs because of its sleep-inducing qualities. Niacin helps stabilize blood sugar, and has been used to treat acne. Niacin has also been extremely beneficial to arthritis sufferers. Dietary vitamin B3, along with other nutrients is important for normal vision and prevention of cataracts.

High cholesterol

Niacin is commonly used to lower elevated LDL (bad) cholesterol and triglyceride (fat) levels in the blood and is more effective in increasing HDL (good) levels than other cholesterol-lowering medications. High doses of niacin have been shown to raise HDL (good) cholesterol, and lower LDL (bad) cholesterol and triglycerides. Niacin has been observed to have substantial benefits in lowering high cholesterol levels. It is particularly effective in raising levels of high-density lipoprotein (HDL or "good cholesterol") levels, but it is less effective at lowering low-density lipoprotein (LDL or "bad cholesterol") levels than some other cholesterol-lowering drugs. Niacin is currently used as one of the first-line treatments of high cholesterol either alone or in combination with other cholesterol-lowering drugs.

Niacinamide, which is also present in vitamin B-3, does not have the same effects as niacin on cholesterol levels. Some studies show that niacin can raise homocysteine levels, which may increase the risk of cardiovascular disease. Of the three forms of niacin, only nicotinic acid and inositol hexaniacinate act as cholesterol-lowering agents. Overall, the use of niacin (nicotinic acid, but not the other form called "niacinamide") to treat or prevent high levels of blood cholesterol and triglycerides and reduce the risk of cardiovascular disease is well substantiated.

Atherosclerosis

Niacin has an effect on blood vessels, allowing them to relax, thus allowing better blood flow to all regions of the body, including hands and feet. Inositol hexaniacinate is one form of niacin that can have this kind of effect on the circulatory system. High doses of niacin medications are used to prevent development of atherosclerosis (plaque along the blood vessels that can cause blockage) and to reduce recurrent complications such as heart attack and peripheral vascular disease (atherosclerosis of the blood vessels in the legs that can cause pain with walking, called intermittent claudication) in those with the condition.

Circulation disorders are painful and often debilitating problems. Intermittent claudication is a circulation disorder characterized by painful cramping in the calf region, usually brought on by walking. Another aggravating disease caused by poor circulation is Raynaud's disease, causing pain and numbness in the extremities when exposed to cold. The combination of niacin and a cholesterol-lowering drug called simvastatin (which belongs to a class known as HmG CoA reductase inhibitors or statins) may dramatically slow the progression of heart disease, reducing risk of heart attack, and even death.

Diabetes

Niacinamide, a chemical in vitamin B-3, has been proposed as a possible therapy to prevent diabetes or delay the need for insulin. Animal studies of niacinamide use in diabetes have suggested that it may increase the time that oral drug treatment is effective and delay the need for insulin injections. Because diabetes is often associated with atherosclerosis and heart disease, people with diabetes may benefit from nutrients that help manage elevated cholesterol levels and high blood pressure. Although niacin has been shown to boost HDL cholesterol and decrease triglyceride and LDL levels, there has been some concern that it may also raise blood sugar levels.

In a recent study of 125 people with diabetes and 343 people without the condition, high doses of niacin (roughly 3000 mg/day), increased blood sugar in both groups, but hemoglobin A1C (considered a better measure of blood sugar over time) actually decreased in the diabetes group over a 60-week follow-up period. For this reason, if you have diabetes, niacin should only be used under the close monitoring of a qualified health care provider.

Osteoarthritis

One form of vitamin B3, niacinamide, appears to increase joint mobility, improve muscle strength, and decrease muscle and joint fatigue in osteoarthritis and rheumatoid arthritis patients.7 250 mg taken at least four times daily appears to show results in three to four months. Niacin has shown anti-inflammatory abilities, making it useful for the treatment of rheumatoid arthritis, a disease characterized by inflammation of the joints. Anti-inflammatory agents provide a stable environment in the joint region, allowing the body to use other compounds to rebuild damaged cartilage.

Persons suffering from osteoarthritis may benefit from therapeutic niacin use to help rebuild worn down cartilage. Some preliminary studies suggest that vitamin B3, as niacinamide, may improve arthritis symptoms, including increasing joint mobility and reducing the amount of anti-inflammatory medications needed. Results from one study suggest that niacinamide, a chemical in vitamin B3, may help to improve flexibility, reduce inflammation and lessen the need for drugs that are commonly used for pain in people with osteoarthritis.

Vitamin B3 (niacin) dosage, intake, recommended daily allowance (RDA)

Recommended daily allowances (RDAs) are defined as the levels of intake of essential nutrients that the Food and Nutrition Board judges to be adequate to meet the known nutrient needs of most healthy persons. Specific recommendations for each vitamin depend on age, gender, and other factors (such as pregnancy). The recommended dietary intake (RDI) of vitamin B3 is 16 mg (niacin equivalents) per day for adult males and 14 mg for adult females, although females who are pregnant require 15 mg per day and those that are lactating require 18mg per day. Much larger doses of vitamin B3 may be given for specific medical conditions under the supervision of a qualified health care professional. The recommended dose of niacin for treating high cholesterol ranges from 1000 mg to 5000 mg each day.

Doses are usually started low and increased slowly to minimize flushing, although aspirin or ibuprofen may reduce the flushing adverse effect. Daily requirements for niacin may be higher for those who have cancer, those who are being treated with isoniazid (for tuberculosis), and people with protein deficiencies. Niacin doses should be divided into 2-3 separate daily doses, or no more than 500-750mg per individual dose). The best way to get the daily requirement of essential vitamins is to eat a balanced diet that contains a variety of foods from the food guide pyramid. Niacin is available in tablet and time-release tablets and capsules. These are available in strengths of 25-mg, 50-mg, 250-mg, and 500-mg.

Sources of vitamin B3 (niacin)

Niacin is widely distributed in foods of both animal and vegetable origin. Niacin is found in dairy products, poultry, fish, lean meats, nuts, and eggs. Legumes and enriched breads and cereals also supply some niacin. Vitamin B3 (Niacin) can be found in beef liver, brewer's yeast, broccoli, carrots, cheese, corn flour, dandelion greens, dates, eggs, fish, milk, peanuts, pork, potatoes, tomatoes, wheat germ, and whole wheat products. Herb that contain niacin include alfalfa, burdock root, catnip, cayenne, chamomile, chickweed, eyebright, fennel seed, hops, licorice, mullein, nettle, oat straw, parsley, peppermint, raspberry leaf, red clover, rose hips, slippery elm, and yellow dock.

Good sources of niacin include yeast, meat, poultry, fish (e.g., tuna, salmon), cereals (especially fortified cereals), legumes, and seeds. Milk, green leafy vegetables, coffee, and tea also provide some niacin. In plants, especially mature cereal grains like corn and wheat, niacin may be bound to sugar molecules in the form of glycosides, which significantly decrease niacin bioavailability.

Niacin is widely distributed in foods of both animal and vegetable origin. Particularly good sources are meat (especially liver), groundnuts and cereal bran or germ. As for other B vitamins, the main source of supply tends to be the staple food. whole-grain or lightly milled cereals, although not rich in niacin, contain much more than highly milled cereal grains. Starchy roots, plantains and milk are poor sources. Beans, peas and other pulses contain amounts similar to those in most cereals.

Other animal and plant sources for Niacin include beef liver, brewer's yeast, broccoli, carrots, cheese, corn flour, dandelion greens, dates, eggs, fish, milk, peanuts, pork, potatoes, tomatoes, wheat germ, and whole wheat products, alfalfa, burdock root, catnip, cayenne, chamomile, chickweed, eyebright, fennel seed, hops, licorice, mullein, nettle, oat straw, parsley, peppermint, raspberry leaf, red clover, rose hips, slippery elm, and yellow dock.

There are three synthetic forms of this vitamin: niacinamide, nicotinic acid, and nicotinamide. Taking a synthetic form of the vitamin can help one avoid the "niacin flush". The flush is temporary and only associated with large doses. However, pure niacin is found in relatively small amounts in most foods. Turkey meat is rich in tryptophan, and so is a good source for Niacin. Niacin is available as a tablet or capsule in both regular and timed-release forms.

The timed-release tablets and capsules may have fewer side effects than the regular niacin; however, the timed-release are more likely to cause liver damage and are therefore not recommended for long-term treatment. Regardless of the form of niacin being used, periodic checking of liver function tests is recommended when high-dose (2 – 6 gm per day) of niacin is used.

Vitamin B3 (niacin) deficiency

Pellagra is a disease caused by niacin deficiency. Pellagra is most often seen in chronic alcoholism, malnutrition and people with multiple vitamin deficiencies. Pellagra causes dermatitis, diarrhoea and dementia. Because of its unique relationship with energy production, vitamin B3 deficiency is often associated with general weakness, muscular weakness, and lack of appetite. There is also a bright red rash resembling sunburn, irritation of the mouth, inflammation and ulceration of the tongue, nausea and vomiting, insomnia, depression, headache dizziness, delusions, hallucinations and anaemia. Skin infections and digestive problems can also be associated with niacin deficiency.

Symptoms of mild deficiency include indigestion, fatigue, canker sores, vomiting, and depression. The most common symptoms of niacin deficiency involve the skin, digestive system, and the nervous system. In the skin, a thick, scaly, darkly pigmented rash develops symmetrically in areas exposed to sunlight. Niacin deficiency also results in burning in the mouth and a swollen, bright red tongue In the United States alcoholism is the prime cause of Vitamin B3 deficiency. Severe niacin deficiency causes pellagra, a disease characterized by mouth sores, skin rashes, diarrhea, and dementia.

Vitamin B3 is used by the body to release energy from carbohydrates. Vitamin B3 or niacin comes in two basic forms: one is called nicotinic acid and the other is called nicotinamide (nicotinamide is also called niacinamide). Niacin (nicotinic acid, nicotinamide) is a water-soluble vitamin whose requirement is partly met by conversion in the body of the essential amino acid tryptophan to niacin. It's also needed to form fat from carbohydrate and to process alcohol. Niacin is helpful in regulating cholesterol. The body uses the water-soluble vitamin B3 in the process of releasing energy from carbohydrates. It is needed to form fat from carbohydrates and to process alcohol. The niacin form of vitamin B3 also regulates cholesterol, though niacinamide does not.

Vitamin B3 contributes to more than 50 vital bodily processes. Among them, vitamin B3 helps convert food into energy, it helps build red blood cell count, synthesizes hormones, fatty acids, and steroids. Vitamin B3 helps maintain skin, nerves, and blood vessels, supports the gastrointestinal tract, and detoxifies certain drugs and chemicals. It is also widely believed in the research community that vitamin B3 helps regulate blood sugar levels.

Vitamin B3 has a powerful, almost drug-like effect, on the lowering of cholesterol levels and triglycerides, dilating blood vessels to improve circulation, and alleviating depression, insomnia, and hyperactivity. A lack of this vitamin can affect every cell in the body. It is carried in the blood and found in all the tissues with the greatest concentrations found in the liver, kidneys, heart, brain and muscle.

A niacin deficiency often leads to a chronic illness called pellagra, characterized by gastrointestinal problems, lesions of the skin, and dementia. Pellagra is characterized by cracked, scaly skin, dementia, and diarrhea. Primary pellagra results from inadequate niacin and/or tryptophan in the diet (mainly in developing countries or poverty stricken areas). Secondary pellagra occurs when there is enough niacin in the diet but something prevents its absorption and processing. It is generally treated with a nutritionally balanced diet and niacin supplements. Niacin deficiency or pellagra may result from inadequate dietary intake of niacin and/or tryptophan.

Other nutrient deficiencies may also contribute to the development of niacin deficiency. Patients with Hartnup's disease, a hereditary disorder resulting in defective tryptophan absorption, have developed pellagra. Carcinoid syndrome, a condition of increased secretion of serotonin and other catecholamines by carcinoid tumors, may also result in pellagra due to increased utilization of dietary tryptophan for serotonin rather than niacin synthesis. Prolonged treatment with the anti-tuberculosis drug, Isoniazid, has also resulted in niacin deficiency.

If left untreated, death is the usual outcome of pellagra. It occurs as a result of niacin (vitamin B-3) deficiency. Niacin is required for most cellular processes. Since tryptophan in the diet can be converted to niacin in the body, both of these need to be deficient for pellagra to develop. Vitamin B3 deficiency is rare, but can occur in alcoholics, individuals with poor or irregular diets (particularly the elderly, pregnant women and infants), and in individuals with medical conditions causing malabsorption from the intestinal tract. Dietary deficiency of niacin tends to only occur in areas of the world where people eat corn as a staple and don't use lime in fertilization.

Niacin deficiency can generally be avoided by regularly including sources of niacin in the diet, including legumes, lean meats, and whole-grain or enriched breads and cereals. Some protein-rich food items that are poor sources of niacin, such as eggs and milk, can also help reduce the risk of niacin deficiency because they contain tryptophan, an amino acid that can be converted into niacin through bacterial action in the body.